/*
 * qrencode - QR Code encoder
 *
 * Copyright (C) 2006-2012 Kentaro Fukuchi <kentaro@fukuchi.org>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
 */

#if HAVE_CONFIG_H
# include "config.h"
#endif
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>

#include "qrencode.h"
#include "qrspec.h"
#include "mqrspec.h"
#include "bitstream.h"
#include "qrinput.h"
#include "rscode.h"
#include "split.h"
#include "mask.h"
#include "mmask.h"

/******************************************************************************
 * Raw code
 *****************************************************************************/

typedef struct {
    int dataLength;
    unsigned char *data;
    int eccLength;
    unsigned char *ecc;
} RSblock;

typedef struct {
    int version;
    int dataLength;
    int eccLength;
    unsigned char *datacode;
    unsigned char *ecccode;
    int b1;
    int blocks;
    RSblock *rsblock;
    int count;
} QRRawCode;

static void RSblock_initBlock(RSblock *block, int dl, unsigned char *data, int el, unsigned char *ecc, RS *rs)
{
    block->dataLength = dl;
    block->data = data;
    block->eccLength = el;
    block->ecc = ecc;

    encode_rs_char(rs, data, ecc);
}

static int RSblock_init(RSblock *blocks, int spec[5], unsigned char *data, unsigned char *ecc)
{
    int i;
    RSblock *block;
    unsigned char *dp, *ep;
    RS *rs;
    int el, dl;

    dl = QRspec_rsDataCodes1(spec);
    el = QRspec_rsEccCodes1(spec);
    rs = init_rs(8, 0x11d, 0, 1, el, 255 - dl - el);
    if(rs == NULL) return -1;

    block = blocks;
    dp = data;
    ep = ecc;
    for(i=0; i<QRspec_rsBlockNum1(spec); i++) {
        RSblock_initBlock(block, dl, dp, el, ep, rs);
        dp += dl;
        ep += el;
        block++;
    }

    if(QRspec_rsBlockNum2(spec) == 0) return 0;

    dl = QRspec_rsDataCodes2(spec);
    el = QRspec_rsEccCodes2(spec);
    rs = init_rs(8, 0x11d, 0, 1, el, 255 - dl - el);
    if(rs == NULL) return -1;
    for(i=0; i<QRspec_rsBlockNum2(spec); i++) {
        RSblock_initBlock(block, dl, dp, el, ep, rs);
        dp += dl;
        ep += el;
        block++;
    }

    return 0;
}

static void QRraw_free(QRRawCode *raw);
static QRRawCode *QRraw_new(QRinput *input)
{
    QRRawCode *raw;
    int spec[5], ret;

    raw = (QRRawCode *)malloc(sizeof(QRRawCode));
    if(raw == NULL) return NULL;

    raw->datacode = QRinput_getByteStream(input);
    if(raw->datacode == NULL) {
        free(raw);
        return NULL;
    }

    QRspec_getEccSpec(input->version, input->level, spec);

    raw->version = input->version;
    raw->b1 = QRspec_rsBlockNum1(spec);
    raw->dataLength = QRspec_rsDataLength(spec);
    raw->eccLength = QRspec_rsEccLength(spec);
    raw->ecccode = (unsigned char *)malloc(raw->eccLength);
    if(raw->ecccode == NULL) {
        free(raw->datacode);
        free(raw);
        return NULL;
    }

    raw->blocks = QRspec_rsBlockNum(spec);
    raw->rsblock = (RSblock *)calloc(sizeof(RSblock), raw->blocks);
    if(raw->rsblock == NULL) {
        QRraw_free(raw);
        return NULL;
    }
    ret = RSblock_init(raw->rsblock, spec, raw->datacode, raw->ecccode);
    if(ret < 0) {
        QRraw_free(raw);
        return NULL;
    }

    raw->count = 0;

    return raw;
}

/**
 * Return a code (byte).
 * This function can be called iteratively.
 * @param raw raw code.
 * @return code
 */
static unsigned char QRraw_getCode(QRRawCode *raw)
{
    int col, row;
    unsigned char ret;

    if(raw->count < raw->dataLength) {
        row = raw->count % raw->blocks;
        col = raw->count / raw->blocks;
        if(col >= raw->rsblock[0].dataLength) {
            row += raw->b1;
        }
        ret = raw->rsblock[row].data[col];
    } else if(raw->count < raw->dataLength + raw->eccLength) {
        row = (raw->count - raw->dataLength) % raw->blocks;
        col = (raw->count - raw->dataLength) / raw->blocks;
        ret = raw->rsblock[row].ecc[col];
    } else {
        return 0;
    }
    raw->count++;
    return ret;
}

static void QRraw_free(QRRawCode *raw)
{
    if(raw != NULL) {
        free(raw->datacode);
        free(raw->ecccode);
        free(raw->rsblock);
        free(raw);
    }
}

/******************************************************************************
 * Raw code for Micro QR Code
 *****************************************************************************/

typedef struct {
    int version;
    int dataLength;
    int eccLength;
    unsigned char *datacode;
    unsigned char *ecccode;
    RSblock *rsblock;
    int oddbits;
    int count;
} MQRRawCode;

static void MQRraw_free(MQRRawCode *raw);
static MQRRawCode *MQRraw_new(QRinput *input)
{
    MQRRawCode *raw;
    RS *rs;

    raw = (MQRRawCode *)malloc(sizeof(MQRRawCode));
    if(raw == NULL) return NULL;

    raw->version = input->version;
    raw->dataLength = MQRspec_getDataLength(input->version, input->level);
    raw->eccLength = MQRspec_getECCLength(input->version, input->level);
    raw->oddbits = raw->dataLength * 8 - MQRspec_getDataLengthBit(input->version, input->level);
    raw->datacode = QRinput_getByteStream(input);
    if(raw->datacode == NULL) {
        free(raw);
        return NULL;
    }
    raw->ecccode = (unsigned char *)malloc(raw->eccLength);
    if(raw->ecccode == NULL) {
        free(raw->datacode);
        free(raw);
        return NULL;
    }

    raw->rsblock = (RSblock *)calloc(sizeof(RSblock), 1);
    if(raw->rsblock == NULL) {
        MQRraw_free(raw);
        return NULL;
    }

    rs = init_rs(8, 0x11d, 0, 1, raw->eccLength, 255 - raw->dataLength - raw->eccLength);
    if(rs == NULL) {
        MQRraw_free(raw);
        return NULL;
    }

    RSblock_initBlock(raw->rsblock, raw->dataLength, raw->datacode, raw->eccLength, raw->ecccode, rs);

    raw->count = 0;

    return raw;
}

/**
 * Return a code (byte).
 * This function can be called iteratively.
 * @param raw raw code.
 * @return code
 */
static unsigned char MQRraw_getCode(MQRRawCode *raw)
{
    unsigned char ret;

    if(raw->count < raw->dataLength) {
        ret = raw->datacode[raw->count];
    } else if(raw->count < raw->dataLength + raw->eccLength) {
        ret = raw->ecccode[raw->count - raw->dataLength];
    } else {
        return 0;
    }
    raw->count++;
    return ret;
}

static void MQRraw_free(MQRRawCode *raw)
{
    if(raw != NULL) {
        free(raw->datacode);
        free(raw->ecccode);
        free(raw->rsblock);
        free(raw);
    }
}


/******************************************************************************
 * Frame filling
 *****************************************************************************/

typedef struct {
    int width;
    unsigned char *frame;
    int x, y;
    int dir;
    int bit;
    int mqr;
} FrameFiller;

static FrameFiller *FrameFiller_new(int width, unsigned char *frame, int mqr)
{
    FrameFiller *filler;

    filler = (FrameFiller *)malloc(sizeof(FrameFiller));
    if(filler == NULL) return NULL;
    filler->width = width;
    filler->frame = frame;
    filler->x = width - 1;
    filler->y = width - 1;
    filler->dir = -1;
    filler->bit = -1;
    filler->mqr = mqr;

    return filler;
}

static unsigned char *FrameFiller_next(FrameFiller *filler)
{
    unsigned char *p;
    int x, y, w;

    if(filler->bit == -1) {
        filler->bit = 0;
        return filler->frame + filler->y * filler->width + filler->x;
    }

    x = filler->x;
    y = filler->y;
    p = filler->frame;
    w = filler->width;

    if(filler->bit == 0) {
        x--;
        filler->bit++;
    } else {
        x++;
        y += filler->dir;
        filler->bit--;
    }

    if(filler->dir < 0) {
        if(y < 0) {
            y = 0;
            x -= 2;
            filler->dir = 1;
            if(!filler->mqr && x == 6) {
                x--;
                y = 9;
            }
        }
    } else {
        if(y == w) {
            y = w - 1;
            x -= 2;
            filler->dir = -1;
            if(!filler->mqr && x == 6) {
                x--;
                y -= 8;
            }
        }
    }
    if(x < 0 || y < 0) return NULL;

    filler->x = x;
    filler->y = y;

    if(p[y * w + x] & 0x80) {
        // This tail recursion could be optimized.
        return FrameFiller_next(filler);
    }
    return &p[y * w + x];
}

#ifdef WITH_TESTS
extern unsigned char *FrameFiller_test(int version)
{
    int width;
    unsigned char *frame, *p;
    FrameFiller *filler;
    int i, length;

    width = QRspec_getWidth(version);
    frame = QRspec_newFrame(version);
    if(frame == NULL) return NULL;
    filler = FrameFiller_new(width, frame, 0);
    if(filler == NULL) {
        free(frame);
        return NULL;
    }
    length = QRspec_getDataLength(version, QR_ECLEVEL_L) * 8
             + QRspec_getECCLength(version, QR_ECLEVEL_L) * 8
             + QRspec_getRemainder(version);
    for(i=0; i<length; i++) {
        p = FrameFiller_next(filler);
        if(p == NULL) {
            free(filler);
            free(frame);
            return NULL;
        }
        *p = (unsigned char)(i & 0x7f) | 0x80;
    }
    free(filler);
    return frame;
}

extern unsigned char *FrameFiller_testMQR(int version)
{
    int width;
    unsigned char *frame, *p;
    FrameFiller *filler;
    int i, length;

    width = MQRspec_getWidth(version);
    frame = MQRspec_newFrame(version);
    if(frame == NULL) return NULL;
    filler = FrameFiller_new(width, frame, 1);
    if(filler == NULL) {
        free(frame);
        return NULL;
    }
    length = MQRspec_getDataLengthBit(version, QR_ECLEVEL_L)
             + MQRspec_getECCLength(version, QR_ECLEVEL_L) * 8;
    for(i=0; i<length; i++) {
        p = FrameFiller_next(filler);
        if(p == NULL) {
            fprintf(stderr, "Frame filler run over the frame!\n");
            free(filler);
            return frame;
        }
        *p = (unsigned char)(i & 0x7f) | 0x80;
    }
    free(filler);
    return frame;
}
#endif


/******************************************************************************
 * QR-code encoding
 *****************************************************************************/

static QRcode *QRcode_new(int version, int width, unsigned char *data)
{
    QRcode *qrcode;

    qrcode = (QRcode *)malloc(sizeof(QRcode));
    if(qrcode == NULL) return NULL;

    qrcode->version = version;
    qrcode->width = width;
    qrcode->data = data;

    return qrcode;
}

void QRcode_free(QRcode *qrcode)
{
    if(qrcode != NULL) {
        free(qrcode->data);
        free(qrcode);
    }
}

static QRcode *QRcode_encodeMask(QRinput *input, int mask)
{
    int width, version;
    QRRawCode *raw;
    unsigned char *frame, *masked, *p, code, bit;
    FrameFiller *filler;
    int i, j;
    QRcode *qrcode = NULL;

    if(input->mqr) {
        errno = EINVAL;
        return NULL;
    }
    if(input->version < 0 || input->version > QRSPEC_VERSION_MAX) {
        errno = EINVAL;
        return NULL;
    }
    if(input->level > QR_ECLEVEL_H) {
        errno = EINVAL;
        return NULL;
    }

    raw = QRraw_new(input);
    if(raw == NULL) return NULL;

    version = raw->version;
    width = QRspec_getWidth(version);
    frame = QRspec_newFrame(version);
    if(frame == NULL) {
        QRraw_free(raw);
        return NULL;
    }
    filler = FrameFiller_new(width, frame, 0);
    if(filler == NULL) {
        QRraw_free(raw);
        free(frame);
        return NULL;
    }

    /* inteleaved data and ecc codes */
    for(i=0; i<raw->dataLength + raw->eccLength; i++) {
        code = QRraw_getCode(raw);
        bit = 0x80;
        for(j=0; j<8; j++) {
            p = FrameFiller_next(filler);
            if(p == NULL)  goto EXIT;
            *p = 0x02 | ((bit & code) != 0);
            bit = bit >> 1;
        }
    }
    QRraw_free(raw);
    raw = NULL;
    /* remainder bits */
    j = QRspec_getRemainder(version);
    for(i=0; i<j; i++) {
        p = FrameFiller_next(filler);
        if(p == NULL)  goto EXIT;
        *p = 0x02;
    }

    /* masking */
    if(mask == -2) { // just for debug purpose
        masked = (unsigned char *)malloc(width * width);
        memcpy(masked, frame, width * width);
    } else if(mask < 0) {
        masked = Mask_mask(width, frame, input->level);
    } else {
        masked = Mask_makeMask(width, frame, mask, input->level);
    }
    if(masked == NULL) {
        goto EXIT;
    }
    qrcode = QRcode_new(version, width, masked);

EXIT:
    QRraw_free(raw);
    free(filler);
    free(frame);
    return qrcode;
}

static QRcode *QRcode_encodeMaskMQR(QRinput *input, int mask)
{
    int width, version;
    MQRRawCode *raw;
    unsigned char *frame, *masked, *p, code, bit;
    FrameFiller *filler;
    int i, j;
    QRcode *qrcode = NULL;

    if(!input->mqr) {
        errno = EINVAL;
        return NULL;
    }
    if(input->version <= 0 || input->version > MQRSPEC_VERSION_MAX) {
        errno = EINVAL;
        return NULL;
    }
    if(input->level > QR_ECLEVEL_Q) {
        errno = EINVAL;
        return NULL;
    }

    raw = MQRraw_new(input);
    if(raw == NULL) return NULL;

    version = raw->version;
    width = MQRspec_getWidth(version);
    frame = MQRspec_newFrame(version);
    if(frame == NULL) {
        MQRraw_free(raw);
        return NULL;
    }
    filler = FrameFiller_new(width, frame, 1);
    if(filler == NULL) {
        MQRraw_free(raw);
        free(frame);
        return NULL;
    }

    /* inteleaved data and ecc codes */
    for(i=0; i<raw->dataLength + raw->eccLength; i++) {
        code = MQRraw_getCode(raw);
        if(raw->oddbits && i == raw->dataLength - 1) {
            bit = 1 << raw->oddbits;
            for(j=0; j<raw->oddbits; j++) {
                p = FrameFiller_next(filler);
                if(p == NULL) goto EXIT;
                *p = 0x02 | ((bit & code) != 0);
                bit = bit >> 1;
            }
        } else {
            bit = 0x80;
            for(j=0; j<8; j++) {
                p = FrameFiller_next(filler);
                if(p == NULL) goto EXIT;
                *p = 0x02 | ((bit & code) != 0);
                bit = bit >> 1;
            }
        }
    }
    MQRraw_free(raw);
    raw = NULL;

    /* masking */
    if(mask < 0) {
        masked = MMask_mask(version, frame, input->level);
    } else {
        masked = MMask_makeMask(version, frame, mask, input->level);
    }
    if(masked == NULL) {
        goto EXIT;
    }

    qrcode = QRcode_new(version, width, masked);

EXIT:
    MQRraw_free(raw);
    free(filler);
    free(frame);
    return qrcode;
}

QRcode *QRcode_encodeInput(QRinput *input)
{
    if(input->mqr) {
        return QRcode_encodeMaskMQR(input, -1);
    } else {
        return QRcode_encodeMask(input, -1);
    }
}

static QRcode *QRcode_encodeStringReal(const char *string, int version, QRecLevel level, int mqr, QRencodeMode hint, int casesensitive)
{
    QRinput *input;
    QRcode *code;
    int ret;

    if(string == NULL) {
        errno = EINVAL;
        return NULL;
    }
    if(hint != QR_MODE_8 && hint != QR_MODE_KANJI) {
        errno = EINVAL;
        return NULL;
    }

    if(mqr) {
        input = QRinput_newMQR(version, level);
    } else {
        input = QRinput_new2(version, level);
    }
    if(input == NULL) return NULL;

    ret = Split_splitStringToQRinput(string, input, hint, casesensitive);
    if(ret < 0) {
        QRinput_free(input);
        return NULL;
    }
    code = QRcode_encodeInput(input);
    QRinput_free(input);

    return code;
}

QRcode *QRcode_encodeString(const char *string, int version, QRecLevel level, QRencodeMode hint, int casesensitive)
{
    return QRcode_encodeStringReal(string, version, level, 0, hint, casesensitive);
}

QRcode *QRcode_encodeStringMQR(const char *string, int version, QRecLevel level, QRencodeMode hint, int casesensitive)
{
    return QRcode_encodeStringReal(string, version, level, 1, hint, casesensitive);
}

static QRcode *QRcode_encodeDataReal(const unsigned char *data, int length, int version, QRecLevel level, int mqr)
{
    QRinput *input;
    QRcode *code;
    int ret;

    if(data == NULL || length == 0) {
        errno = EINVAL;
        return NULL;
    }

    if(mqr) {
        input = QRinput_newMQR(version, level);
    } else {
        input = QRinput_new2(version, level);
    }
    if(input == NULL) return NULL;

    ret = QRinput_append(input, QR_MODE_8, length, data);
    if(ret < 0) {
        QRinput_free(input);
        return NULL;
    }
    code = QRcode_encodeInput(input);
    QRinput_free(input);

    return code;
}

QRcode *QRcode_encodeData(int size, const unsigned char *data, int version, QRecLevel level)
{
    return QRcode_encodeDataReal(data, size, version, level, 0);
}

QRcode *QRcode_encodeString8bit(const char *string, int version, QRecLevel level)
{
    if(string == NULL) {
        errno = EINVAL;
        return NULL;
    }
    return QRcode_encodeDataReal((unsigned char *)string, strlen(string), version, level, 0);
}

QRcode *QRcode_encodeDataMQR(int size, const unsigned char *data, int version, QRecLevel level)
{
    return QRcode_encodeDataReal(data, size, version, level, 1);
}

QRcode *QRcode_encodeString8bitMQR(const char *string, int version, QRecLevel level)
{
    if(string == NULL) {
        errno = EINVAL;
        return NULL;
    }
    return QRcode_encodeDataReal((unsigned char *)string, strlen(string), version, level, 1);
}


/******************************************************************************
 * Structured QR-code encoding
 *****************************************************************************/

static QRcode_List *QRcode_List_newEntry(void)
{
    QRcode_List *entry;

    entry = (QRcode_List *)malloc(sizeof(QRcode_List));
    if(entry == NULL) return NULL;

    entry->next = NULL;
    entry->code = NULL;

    return entry;
}

static void QRcode_List_freeEntry(QRcode_List *entry)
{
    if(entry != NULL) {
        QRcode_free(entry->code);
        free(entry);
    }
}

void QRcode_List_free(QRcode_List *qrlist)
{
    QRcode_List *list = qrlist, *next;

    while(list != NULL) {
        next = list->next;
        QRcode_List_freeEntry(list);
        list = next;
    }
}

int QRcode_List_size(QRcode_List *qrlist)
{
    QRcode_List *list = qrlist;
    int size = 0;

    while(list != NULL) {
        size++;
        list = list->next;
    }

    return size;
}

#if 0
static unsigned char QRcode_parity(const char *str, int size)
{
    unsigned char parity = 0;
    int i;

    for(i=0; i<size; i++) {
        parity ^= str[i];
    }

    return parity;
}
#endif

QRcode_List *QRcode_encodeInputStructured(QRinput_Struct *s)
{
    QRcode_List *head = NULL;
    QRcode_List *tail = NULL;
    QRcode_List *entry;
    QRinput_InputList *list = s->head;

    while(list != NULL) {
        if(head == NULL) {
            entry = QRcode_List_newEntry();
            if(entry == NULL) goto ABORT;
            head = entry;
            tail = head;
        } else {
            entry = QRcode_List_newEntry();
            if(entry == NULL) goto ABORT;
            tail->next = entry;
            tail = tail->next;
        }
        tail->code = QRcode_encodeInput(list->input);
        if(tail->code == NULL) {
            goto ABORT;
        }
        list = list->next;
    }

    return head;
ABORT:
    QRcode_List_free(head);
    return NULL;
}

static QRcode_List *QRcode_encodeInputToStructured(QRinput *input)
{
    QRinput_Struct *s;
    QRcode_List *codes;

    s = QRinput_splitQRinputToStruct(input);
    if(s == NULL) return NULL;

    codes = QRcode_encodeInputStructured(s);
    QRinput_Struct_free(s);

    return codes;
}

static QRcode_List *QRcode_encodeDataStructuredReal(
    int size, const unsigned char *data,
    int version, QRecLevel level,
    int eightbit, QRencodeMode hint, int casesensitive)
{
    QRinput *input;
    QRcode_List *codes;
    int ret;

    if(version <= 0) {
        errno = EINVAL;
        return NULL;
    }
    if(!eightbit && (hint != QR_MODE_8 && hint != QR_MODE_KANJI)) {
        errno = EINVAL;
        return NULL;
    }

    input = QRinput_new2(version, level);
    if(input == NULL) return NULL;

    if(eightbit) {
        ret = QRinput_append(input, QR_MODE_8, size, data);
    } else {
        ret = Split_splitStringToQRinput((char *)data, input, hint, casesensitive);
    }
    if(ret < 0) {
        QRinput_free(input);
        return NULL;
    }
    codes = QRcode_encodeInputToStructured(input);
    QRinput_free(input);

    return codes;
}

QRcode_List *QRcode_encodeDataStructured(int size, const unsigned char *data, int version, QRecLevel level)
{
    return QRcode_encodeDataStructuredReal(size, data, version, level, 1, QR_MODE_NUL, 0);
}

QRcode_List *QRcode_encodeString8bitStructured(const char *string, int version, QRecLevel level)
{
    if(string == NULL) {
        errno = EINVAL;
        return NULL;
    }
    return QRcode_encodeDataStructured(strlen(string), (unsigned char *)string, version, level);
}

QRcode_List *QRcode_encodeStringStructured(const char *string, int version, QRecLevel level, QRencodeMode hint, int casesensitive)
{
    if(string == NULL) {
        errno = EINVAL;
        return NULL;
    }
    return QRcode_encodeDataStructuredReal(strlen(string), (unsigned char *)string, version, level, 0, hint, casesensitive);
}

/******************************************************************************
 * System utilities
 *****************************************************************************/

void QRcode_APIVersion(int *major_version, int *minor_version, int *micro_version)
{
    if(major_version != NULL) {
        *major_version = MAJOR_VERSION;
    }
    if(minor_version != NULL) {
        *minor_version = MINOR_VERSION;
    }
    if(micro_version != NULL) {
        *micro_version = MICRO_VERSION;
    }
}

char *QRcode_APIVersionString(void)
{
    return VERSION;
}

void QRcode_clearCache(void)
{
    QRspec_clearCache();
    MQRspec_clearCache();
    free_rs_cache();
}
